Question

To synthesize the given compound via an $S_{N}2$ reaction, which of the following options is appropriate:

• A. 5-chloro-pentan-1-ol should be treated with a base like $O{H}^{-}$
• B. 5-chloro-pentan-2-ol should be treated with a base like $O{H}^{-}$
• C. 5-chloro-pentan-3-ol should be treated with a base like $O{H}^{-}$
• D. None of the above

Answer 1

The correct option is A

5-chloro-pentan-1-ol should be treated with a base like $O{H}^{-}$

The given compound is a cyclic ether. The base $O{H}^{-}$ abstracts a proton and the resulting oxygen (anion) nucleophile displaces chloride in an intramolecular $S_{N}2$:

Small amounts of the pentane-1,2-diol is also formed.